Object-Oriented Programming - Is This Really Polymorphism?

There should be no sequence of events without, you know, reaching exogenously to the file system and kind of going, did you write a file or whatever? I shouldn't be able to puppeteer an object that I've been given and work out what it is just by using the API. It's not like you go, well, if it's this type, you have to call free. And this one, you don't have to call the free thing, because it's not actually allocating anything. But again, does this really rise to the level of like the top five principles that you need to be aware of when you're writing code? Like, no, not